What do you mean?
I just looked at their transfer and they seem to be normal transfers that are not spammy messages asking users to do things. Some services require the use of memos to operate, and some services message their current users with memos.
It isn't inherently a bad practice. When it is used to spam the blockchain with useless data and phishing scams, its more than just a little annoying.
RE: Top 25 Users That Sent Messages In Transfers Via Memos for 2017-10-30