Except its not a suicide unit. And has never been designed as one. Though I agree that it is poorly a designed one - the argument you think you are making isn’t as strong a counter-argument as you think it is.
Still, I will humour you. In what way does it break the rules that have been laid out for zone control units? It has a short range, which means you can pick it off with longer ranged units. It has a very, very slow reload time to make up for the fact that it is a splash unit (during which it is effectively wasted supply), along with the fact that it takes a full second and a half to fire. It does burrow itself quickly, but unlike the long range lurker this is less of an issue (though still an issue) for the mine than it is for a unit that has 10 range. Even so, I would still say it’s not exactly a well designed unit.
For lurkers specifically, they are mobile siege units that take no time to set up and still do splash damage.
A siege unit can have a few properties. Either it can have long range and splash damage, but be immobile, take time to set up and squishy. Alternatively, it can have long range, mobility and not take time to set up, but be squishy and have no splash damage.
The first option is the siege tank. It has great range (and requires a spotter to use full range) and incredible damage output but is squishy and immobile. This means that it takes time to get into position, and its immobility can be abused to get around and hit places it isn’t in. It also means that it takes time to get into position and get into its “siege” mode, which means that a player can easily catch it out of position and kill the unit if it isnt set up because it takes a long time to set up. And, as an additional measure, the siege tank has a minimum firing range, within which it is vulnerable. It’s counters are clear cut. There are ways to engage it to pick off tanks, and ways to avoid it if its in a sieged position.
Alternatively, you have a unit like the tempest, and to some extent the broodlord.
Both units are long range artillary units that are, as far as siege units are concerned, reasonably mobile in the fact that they have some limited ability to kite and maintain a maximum firing range without the need for a lengthy set up into a siege mode. However, as a trade off, neither unit gets any form of splash damage on their attacks, though the broodlord does have broodlings that mess with pathing which makes kiting easier, and both are reasonably frail units as far as air units specifically go. Like the tank, their counters are relatively clear-cut as well. The tempest is vulnerable to reasonable numbers due to its lack of splash, and the broodlord similarly so.
The lurker however, is all of these things. Theyre tanky for a ground unit. They have long range, they have no setup time, they are extremely mobile (being one of the fastest units in the game), and they do splash damage. Not to mention they are also cloaked units which adds a whole other level of difficulty to dealing with something that already has few, if any clear cut counters, which are, at best, soft counters when combined with other units, and at worst, straight up ineffective. You cannot catch them out of position, because they can burrow almost literally instantly on the off chance that you do catch them above ground. If somehow you manage to bypass creep and overlords alike and circumvent them, they’re so fast that they can reposition within moments to be where they weren’t and deal with, say, a doom drop into your main, even when you’re out defending a fourth, fifth, sixth or seventh base. Thus, your only real choice is to engage on them yourself, which is exactly what lurkers want - they want you to engage into a pre-set position, which you have no choice but to engage into.
Now if that said, it is possible to deal with Lurkers. Very, very difficult, regardless of if youre terran or protoss, but possible nonetheless. That does NOT make them well designed units, and that doesnt mean they are not overtuned. Broodlords infestor in WoL was wildly overtuned, even though it didnt have a 100% win-rate. The same applies to the lurker now.