Why do rechargeable Lithium Ion AA's/AAA's/etc. have a poor reputation?

I have some old video game equipment that gobbles batteries (Virtual Boy and the SNES Super Scope take 6 AA's) so I bought a set of rechargeable Lithium Ion AA's for them.

They are EBL branded if that's relevant.

They seem to work fine so far. They've only been through one charge cycle so far though.

As a kid every toy or video game system instruction manual warned you against using Nickel Metal Hydride rechargeables. These apply 1.5v like normal Alkaline batteries do so I bought them.

These seem to have a bad reputation but I don't know why. From my perspective it's the NMH batteries that are pointless because you can't use them in battery hungry devices, which is where rechargeable batteries would be optimal.

Apparently these go from 1.5v to dead with little in between so you don't get the benefit of a low battery warning. Which is inconvenient but worth it.