I feel that disallowing Multiattack would be kind of a kneejerk reaction that doesn't take into account all the great things other companions can do.
Giant Badger has mediocre accuracy, no skills, weak Perception, no knockdown, no grapple, no poison, no charge attack, no relentless, no wallcrawling, no swim speed, and no fly speed. Its only real trick is burrow.
Looking at just the CR 1/4 list, there are plenty of reasons to pick companions other than the giant badger, even with multiattack factored in.
A good house rule, however, might be to buff those other pets by adding the ranger's proficiency bonus to the DCs of knockdown, grapple, poison, etc. This was, IMO, a glaring oversight on the part of the design team.