In my experience, a lot of the MikroTik hardware has been underpowered (struggling to get decent routing and IPSEC performance), so I’ll agree with you on that point.
But I’ve found a lot of Ubiquiti hardware to be extremely high quality given how cheap it is. At my office, we installed seven new 802.11ac Ubiquiti access points for as much as it would have cost to add one more 802.11n to our Cisco system (apart from wanting 802.11ac, we also decided to decommission the Cisco because the controller would periodically crash every two months or so).
To get the number of 10GbE interfaces and performance the EdgeRouter Infinity has (for $1600) in a Cisco would cost multiple times the price there too.
I don’t know if I’d trust it for service-provider infrastructure, but we’ve replaced a lot of enterprise Cisco stuff in our office networks with Ubiquiti and only had a good experience.