Not exactly true, depending on the dosing pump you get they are rather affordable. The pump I got was cheaper than my lights, filter, and complete CO2 setup. Regardless if it is freshwater/saltwater it is a convenience thing and not needed for ether. I have paid nearly just as much for my planted as I have for my 100G reef tank. They both have the same premis. In a reef tank you are dosing the corals, in a freshwater you are dosing the plants. Is it needed? No, but it is not needed in ether setup depending on the plants or corals you are keeping. For me I can be away from my tank anywhere from 24-48 hrs or more at a time because of my line of work. For me it just makes sense to have one.
I got to agree here. Sure, for most it's a luxury but I have a much more primitive setup and it was the only way I could keep a high tech tank. I often got home at 3-5AM, got up at 11am (if I could), only to be out of the house by 12. It might have been mine, it may have been my girlfriend's (now wife). The last thing I was concerned about was dosing my tank, if I was even at where my tank was at. Some days I was home all day and I would have enough time to trim, water change all that but no way I could keep up. For me, at that time, it's was like saying automating lighting or co2 was overkill, for most, they could turn there lights and co2 on before work, turn off when they come home. On the weekends or a day off, see how the tank looks. I feel you 100% on this.
Sorry for the rant, people said the same thing when I set up mine. I don't have that lifestyle anymore and don't miss it (well, I kind of do but wouldn't go back unless the money was right) but I absolutely needed that in my setup. Now I am trying to ween my way off of it haha.