The underlying principles (legal, that is, not moral) are quite complex here. ICASA's role (believe it or not) is to ensure a sustainable, competitive market. The EC Act, for all its flaws, creates a framework for such a market. The underlying policy is not a completely open market for infrastructure (ECNS) competition. Whilst there is nothing wrong with a completely open market in principle (moral, that is, not legal), it isn't the most efficient in economic terms, which is why such markets are rare around the world.
A typical effective regulator (let's exclude ICASA for the moment) will establish a licensing model that ensures competition between players who are likely to be able to make a difference, and actually compete. In particular, scarce resources (like spectrum, or, eventually, space for ducts in roads) should not simply be allocated to anyone who walks through the door, or is a friend of the minister.
So, to take the Altech case:
There are plenty of calls for a completely open market for infrastructure competition. This is equivalent to calling for the scrapping of the EC Act, and its replacement by a couple of somewhat confused statements by a minister. That would fly in the face of the (fairly open and fair) parliamentary process that created the Act in the first place.
Altech's stand is therefore (in legal, and probably moral, terms) a defence of the entire democratic process. We elected a parliament to create laws that give us the best outcome based on multiple social, economic and legal inputs, not to have these laws overridden by ministers on a bad hair day.
Whilst Altech's case may delay the final implementation of the Act, the alternative is not as great as it sounds. Currently, there are players like Smile (yes, you should be asking, "Who?") who have been earmarked for ECNS licences, yet a player like Altech (read, Autopage, Netstar, UEC [DSTV decoder manufacturer] etc) has been (probably intentionally) excluded from the minister's private list. Players like IS are on the list not because of any inherent good that the represent economically, but because they have friends in high places. Is this the kind of legal framework we want in telecoms? Well done, Altech. Now we just need to get the legal system working a bit faster.