At the end of the day you were only two minutes from touchdown and the Captain wanted you to dump the gear. Just do it and it is no big deal. Half the time he or she may have seen something you missed while you were concentrating on your low drag approach anyway ie an aircraft taking their time to line up or a tailwind starting to come in or the preceding aircraft looking like they'l miss their high speed. Or, that particular Captain may just be more conservative than you and that is how they operate. Or, they may have just had to do a go around last week because of an FO who was less highly skilled than yourself cocked it up, so now they are a little cautious.
Basically if the Captain thinks it's a good idea to take the gear at 2100ft then who's place is it to say otherwise?
The main thing is that it should not be taken personally. It is not a slight on your ability to fly an approach, it is simply what the PIC thinks is best at that moment. Don't hold it against them for being conservative, one day you might decide to be a fraction more conservative too.....that happens.