Sure, they are pretty bad, but the alternatives aren't much better.

If it had remained the same, panther and killshot would have been nerfed out of the meta, upsetting a lot of players- myself included  https://9apps.ooo/ .

If it had stayed the same but they got upgraded to epic, it would have created a large power imbalance for new players- not that that would be bad if matchmaking worked, but it doesn't.

If they just got removed completely, it would also create a very noticable lack of good early game mechs.

I've been playing on a new account with slingshot and puma, and as much as they suck in general, they do serve the same purpose as all the other starter mechs- to get you started.

That being said, they still could have gone about it much better, and the only real reason to make starter mechs bad is to make people want to pay for good starter mechs.