I have thought about this question - and the discussion within this thread - for a couple of days now. And while it is beyond me to respond to it in learned or philosophical manner, I have decided to add my view in a simple manner of how I have experienced either perspective.
The first time I got introduced to Buddhism was in my teens (quite a while ago
). In my area, the Tibetan/Mahayana school has been most prevalent so this was my first connection. The philosophy appealed to me, the related practice and especially the prominent and very emphatic focus on a guru-/veneration-based approach was not at all attractive to me (I guess I have some issues with "authority figures"). I wasn't aware of any "other" Buddhist approach by then and frankly, I was totally put off.
20 years later, I found back to engaging the "Buddhist attraction" when my ex-boyfriend unexpectedly died and I got into dealing with his death by reading Sogyal Rinpoche's Tibetan Book of Living and Dying. Again, there was a lot of stuff which I simply cannot accept; but also there was a lot of stuff which I felt was worth exploring in more detail.
This was in 2006 and my journey of understanding more about Buddhism has actually brought me here. Because in starting with the Tibetan style and Mahayana approach (without realizing then or even now the whole scale of Mahayana approaches) , I found the Thai forest tradition. And while my reaction the Tibetan teachings remained ambivalent, the teachings of Ajahn Chah and his disciples spoke to me in a way I could unhesitantly relate to: the teaching elements are there, also the compassion and wisdom, but without the rituals and heavy reliance of guru-/lineage transmission which I personally found so off-putting in the Tibetan texts I read.
I guess you could argue that by following the teachings of Ajahn Chah's disciples "lineage", I am not acting overly differently to the Tibetan lineage selection. But to me, this choice is based on what I am able to understand and work with.
So, to summarise from my perspective of a beginner of Theravada practice, a Mahayana perspective brought me here, in the end. So, either perspective can be useful to guide you to "your" practice, in one way or the other. That's sufficiently useful in my books